A vertebral endplate chisel having upper and lower shaving portions, and a non-cutting guide integrally connected to and extending between the shaving portions and adapted to center the chisel within the disc space so that equal amounts of bone are removed from each endplate by the shaving portions as the chisel moves through the disc space. The apparatus for use in this method preferably comprises: a pure culture of autotrophic, hydrogen-oxidizing denitrifying bacteria; a hydrogen generator; a flow-through bioreactor; and a filtration unit. A first portion of the statistics indicates at least one relationship between at least a portion of the plurality of columns, while a second portion of the statistics includes single column statistics.